Cabrales Pedro, Tsai Amy G, Frangos John A, Briceño Juan C, Intaglietta Marcos
University of California-San Diego, Department of Bioengineering, 0412, 9500 Gilman Dr., La Jolla, CA 92093, USA.
Am J Physiol Heart Circ Physiol. 2004 Jul;287(1):H320-30. doi: 10.1152/ajpheart.01166.2003.
The oxygen transport capacity of fluorocarbons was investigated in the hamster chamber window model microcirculation to determine the rate at which oxygen is delivered to the tissue in conditions of extreme hemodilution [hematocrit (Hct) 11%]. Hydroxyethlyl starch (HES 200; 200 kDa molecular mass) was used as a plasma expander for two isovolemic hemodilutions performed with 10% HES 200 until a Hct of 65%. A third step reduced the Hct to 75% of baseline and was performed with either HES 200 or a 60% perfluorocarbon (PFC) emulsion. Comparisons of HES 200-only-hemodiluted animals versus 4.2 g/kg PFC emulsion-hemodiluted animals were made at 21% and 100% normobaric oxygen ventilation. It was found that systemic and microvascular oxygen delivery was 25% and 400% higher in the PFC animals compared with HES 200 animals, respectively, showing that PFCs deliver oxygen to the tissue when combined with hyperoxic ventilation in the present experiments, with no evidence of vasoconstriction or impaired microvascular function. Oxygen ventilation (100%) led to a positive base excess for the PFC group (5.5 +/- 2.5 mmol/l) versus a negative balance (-0.8 +/- 1.4 mmol/l) for the HES 200 group, suggesting that microvascular findings corresponded to systemic events.
在仓鼠室窗模型微循环中研究了氟碳化合物的氧运输能力，以确定在极端血液稀释（血细胞比容（Hct）为11%）条件下氧气输送到组织的速率。羟乙基淀粉（HES 200；分子量200 kDa）用作血浆扩容剂，进行两次等容血液稀释，用10%的HES 200直至血细胞比容达到65%。第三步将血细胞比容降至基线的75%，使用HES 200或60%的全氟碳化合物（PFC）乳剂进行。在常压氧通气21%和100%时，对仅用HES 进行血液稀释的动物与用4.2 g/kg PFC乳剂进行血液稀释的动物进行了比较。结果发现，与HES 200动物相比，PFC动物的全身和微血管氧输送分别高出25%和400%，表明在本实验中，PFC与高氧通气联合使用时可将氧气输送到组织，且没有血管收缩或微血管功能受损的证据。氧通气（100%）导致PFC组出现正碱剩余（5.5±2.5 mmol/l），而HES 200组为负平衡（-0.8±1.4 mmol/l），这表明微血管的结果与全身情况相符。
